1. Field
The following description relates to a beamforming vector that may be used by multiple transmitters in a communication system that employs Cooperative Multi-Point (CoMP) communication.
2. Description of Related Art
In data communication systems, it is desirable for a large amount of data to be transmitted at a low Bit Error Rate (BER) regardless of the existence of interference and noise. In particular, to transmit large amounts of data technologies for multi-cell communication systems have been developed. In multi-cell communication systems, a relatively large amount of interference may occur in mobile stations located at cell edges. The interference results in a reduction in the capacity of mobile stations and communication systems.
To increase the capacity of mobile stations at cell edges, technologies for Cooperative Multi-Point (CoMP) communication are being developed. In a CoMP communication scheme, a plurality of base stations may cooperate with each other to transmit data to at least one mobile station. The plurality of base stations may design an optimal beamforming matrix based on channels between the base stations and the at least one mobile station.
A scheme for implementing the CoMP communication may be classified into a joint processing scheme and a coordinated scheduling/beamforming scheme. In the joint processing scheme, each of the base stations share the transmitted data as well as information about the channels, whereas in the coordinated scheduling/beamforming scheme, each of the base stations do not share the data. However, in the coordinated scheduling/beamforming scheme, the base stations may cooperate with each other to perform scheduling and may design a beamforming vector based on a result of the scheduling.
Both the joint processing scheme and the coordinated scheduling/beamforming scheme employ algorithms for designing a beamforming vector. Among the various algorithms, a linear beamforming algorithm has a relatively low complexity. The linear beamforming algorithm includes a zero-forcing scheme and a Joint Leakage Suppression (JLS) scheme.
Generally, the JLS scheme has a superior performance in comparison to the zero-forcing scheme in a signal-to-noise ratio (SNR), when applied to mobile stations in cell edges. In other words, the JLS scheme is more suitable for the CoMP communication than the zero-forcing scheme. The JLS scheme uses an eigenvalue decomposition and matrix inverse operation to design a beamforming vector. However, the eigenvalue decomposition and matrix inverse operation may increase the overall complexity of the scheme.